We're dividing 42668 by 21 
Let's see how many times 21 fits into 42668.

Going ahead to step 1:
21 can be fit into 4 0 times, resulting in a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Append the next digit (2) from the dividend to 4 and continue with: 42 / 21

Going ahead to step 2:
When dividing 42 by 21, we get 2 with a remainder of 0.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we take 42 away from 42, we end up with 0.
Include the next digit (6) from the dividend after 0, then repeat: 6 / 21

Advancing to step 3:
If we divide 6 by 21, we get 0 and a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 20.0
The remainder is 6 after subtracting 0 from 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 21

Step 4:
The number 21 fits into 66 3 times, leaving a remainder of 3.
The number 3 becomes the next digit in our result. 
Result so far: 203.0
Subtracting 63 from 66 leaves us with 3.
Grab the next digit (8) from the dividend, add it to 3, then carry on: 38 / 21

Going ahead to step 5:
38 divided by 21 is 1 with a remainder of 17.
Use 1 as the next digit of our solution. 
Result so far: 2031.0
If we subtract 21 from 38, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Let's proceed to step 6:
21 can be fit into 170 8 times, resulting in a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 2031.8
The remainder is 2 after subtracting 168 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
When dividing 20 by 21, we get 0 with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 2031.8
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 8:
200 divided by 21 is 9 with a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 2031.809
Deduct 189 from 200 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 9:
When dividing 110 by 21, we get 5 with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 2031.8095
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 10:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 2031.80952
If we take 42 away from 50, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 11:
When dividing 80 by 21, we get 3 with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 2031.809523
The remainder is 17 after subtracting 63 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 12:
If we divide 170 by 21, we get 8 and a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 2031.8095238
If we subtract 168 from 170, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 13:
If we divide 20 by 21, we get 0 and a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 2031.8095238
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Our division results in 2031.8095238 with a remaining 2e-08.